Large group therapy involves a therapist/therapists working with more than 10-12 people at a time. In this context the group dynamics become more chaotic than is usual in the more managed context of regular group therapy settings and crowd phenomena become more apparent. For this reason it is not usual to run such groups as a psychotherapy service, although they are useful for limited training purposes because the dynamic issues are perhaps more obvious.

Their main use in clinical practise is for the delivery of practical information in a didactic context that limits the playing out of group dynamics.